1. Field of the Present Invention
The present invention generally relates to the field of data processing systems and more particularly to a system and method for monitoring the insertion and removal of circuit boards or blades in a data processing system.
2. History of Related Art
Data processing systems in general and server-class systems in particular are frequently implemented with a server chassis or cabinet having a plurality of racks. Each cabinet rack can hold a rack mounted device (also referred to herein as a blade or server blade) on which one or more general purpose processors and/or memory devices are attached. The racks are vertically spaced within the cabinet according to an industry standard displacement (the “U”). Cabinets and racks are characterized in terms of this dimension such that, for example, a 42U cabinet is capable of receiving 42 1U rack-mounted devices, 21 2U devices, and so forth. Dense server designs are also becoming available, which allow a server chassis to be inserted into a cabinet rack, thus allowing greater densities than one server per 1U. To achieve these greater densities, the server chassis may provide shared components, such as power supplies, fans, or media access devices which can be shared among all of the blades in the server blade chassis.
In a rack-mounted server blade environment, the ability to hot plug server blades is a standard feature. Hot plugging refers to the ability to install and remove a blade without turning off power to the cabinet. When a new server blade is initially installed into a cabinet, the blade generally contains no operating system and no persistent data. Making a newly added blade functional requires deployment software that is capable of recognizing that a new blade has been added, determining the blade characteristics to uniquely identify the blade, powering the blade on, and assigning a functional boot image to the blade. For purposes of this disclosure, a boot image refers generally to software stored in persistent storage that is executed following a power-on or system reset event. The boot image may execute a self test (commonly referred to as a power on self test or POST), load a basic I/O system (BIOS) into memory, and install a functional operating system.
While the rack design beneficially facilitates the easy configuration and expansion of server systems, it also allows server blades to be moved about freely within a cabinet or between different cabinets. The mobility of rack-mounted server blades enabled by cabinet designs can increase the difficulty of monitoring the exact location of blades within a system or group of systems. It is desirable, nevertheless, to be able to determine the location of individual server blades within a system. It would be highly desirable, therefore, to implement a system and method that automates the tracking of server blades within the system. It would be further desirable if the implemented solution is able to determine when blades have been recently installed or removed from a particular rack. It would be still further desirable if the implemented solution did not substantially increase the cost or complexity of the system.